1. Field of the Invention
This invention pertains generally to conveyor frames and more particularly, to web brackets for open frame continuous conveyor systems.
2. Related Art
A Continuous Conveyor System (CCS) is a mechanism for transporting articles from one location to another. In a common CCS, there is a belt in an elongated loop configuration where a top portion of the belt loop is above a bottom portion of the belt loop. The belt is driven round and round by a motor. An article is placed on the belt and is held in place on the belt by gravity. As the belt moves, the article rides along the belt from a first point to another point.
The CCS may include legs to support the conveyor belt a distance above the ground/floor. The System may include guide rails to retain articles on the conveyor belt.
Continuous Conveyor Systems are used in the food and pharmaceutical industries. During operation, small pieces of meat, powders and/or other debris collect on or within the Continuous Conveyor System. Accordingly, the CCS requires routine cleaning which is labor intensive and/or not effective to sanitize the CCS. The cleaning CCS is made difficult by debris collecting within casings, in lap seams between components and/or in the interstitial spaces around penetrating fasteners.
An improved CCS is an Open Frame Continuous Conveyor System (“OFCCS”) as described in U.S. Pat. No. 6,591,979 issued to Applicant, Daniel P. Karpy, on Jul. 15, 2003 and incorporated herein by reference. An OFCCS is easier to clean than a common CCS.
In an OFCCS there is a Frame Rail (also called an Elongated Conveyor Support) that is like a horizontal spinal cord. When the OFCSS is fully assembled, the Frame Rail is located between the top and bottom portions of the endless conveyor loop and is approximately the length of the loop.
There are Web Brackets (also called Frame Members) mounted to the Frame Rail in a perpendicular fashion and spaced apart along the Frame Rail. When the OFCSS is fully assembled, the Web Brackets are located between the top and bottom portions of the continuous conveyor loop. The Web Bracket is of a sufficient length that its distal edges extends beyond the width conveyor belt.
At each of the distal ends of a Web Bracket, there is an arm in the plane of the bracket that further extends outward. Formed at the end of the arm is a right angle bend. This results in a Skid Rail Tab (also called a leg.) The Skid Rail Tab is for the attachment of a Skid Rail (also called a Track Guide or Wearstrip.)
A Skid Rail is an elongated strip on which the conveyor belt slides. The Skid Rail has a wide width and a short height and is said to be lying on Flat. The Skid Rail is attached to the Skid Rail Tab through a connector aperture in the Skid Rail Tab, an aperture in the Skid Rail and a fastener such as a bolt and nut.
As mentioned, the conveyor belt slides along the Skid Rail and there is abrasion of the surface of the Skid Rail. The short height of the Skid Rail becomes the limiting dimension for the life of the Skid Rail. That is, the short height defines an abrasion zone. A Skid Rail lying on flat provides strength for supporting articles on the conveyor belt; but, it does not provide great strength.
Typically, at the distal of the Web Bracket, there are additional arms for the attachment of support legs and guide rails.
In a typical application of OFCCS in the food and pharmaceutical industries there is a daily routine in which the OFCCS is run for 1 to 2 eight hour shifts and one eight hour sanitizing shift (usually at night.) During this sanitizing shift the conveyor is sanitized by in-place cleaning, followed by partial disassembly, followed by an out-of-place cleaning of some components and then re-assembly.
In more detail, the cleaning shift is begun with “clean in place” (CIP) cleaning to attempt to remove solids and visible dirt. A CIP cleaning is begun by foaming of the conveyor frame with a caustic foam to disinfect. This is followed by a hot water rinse. The CIP cleaning can leave behind solids in the lap seam between a Skid Rail and the Skid Rail Tab and in the interstitial spaces of penetrating fasteners. There can be thermal expansion of the Skid Rail with concomitant bowing of the Skid Rails between attachment points at successive Web Brackets. This in turn results in an uneven carrying surface for the belt which in turn causes articles to shift as they ride on the belt and higher wear of the Skid Rail.
The CIP is followed by a “clean off place/premises” (COP) cleaning of some components. This COP cleaning can be somewhat laborious. More precisely, there is a disassembly of the Skid Rails from the Web Brackets. This disassembly requires the use of tools to remove the penetrating fasteners that attach the Skid Rails to the Skid Rail Tabs of the Web Bracket. The Skid Rails and other removed components are put in a tank for a washing cycle. This is followed by re-assembly. As with disassembly, reassembly requires the use of tools and is somewhat laborious.
There is a need for an improved OFCCS which does not require tools for disassembly of Skid Rails for a COP cleaning.
There is a need for an improved OFCCS with Skid Rails that have enhanced mechanical strength compared to that in current OFCCS.
There is a need for an improved OFCCS with Skid Rails that wear longer compared to that in current OFCCS.
There is a need for an improved OFCCS that has web brackets that provides the utility of securing Skid Rails that is less expensive and easier to manufacture.
There is a need for an improved OFCCS that has web brackets that are stronger and more resistant to longitudinal bending
There is a need for an improved OFCCS that reduces or eliminates heat deflection of Skid Rails during CIP.
There is a need for an improved OFCCS that reduces or eliminates solids remaining in lap seams and the interstitial spaces of penetrating fasteners after CIP.
The present invention satisfies these needs, as well as others, and generally overcomes the presently known deficiencies in the art.